TITLE: Dusty Cactus
NAME: Michael Hunter
COUNTRY: USA
EMAIL: intertek@one.net
WEBPAGE: http://www.interactivetechnologies.net
TOPIC: Desert
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: d_cactus.jpg
ZIPFILE: d_cactus.zip
RENDERER USED: 
    3D Studio Max Version 6

TOOLS USED: 
    3D Studio Max, PhotoShop (for texture maps)

RENDER TIME: 
    3 Hours 49 Minutes

HARDWARE USED: 
    Pentium 4 1.8 GHz 261 MB RAM


IMAGE DESCRIPTION: 

As the topic notes said: "...Anything that evokes 'desert' in your mind" So I
thought about the desert. The first image in my head was a vast sea of sand.
Then the three wise men and their camels walked into it. And they start to
argue about the map and being too cheap to pay for AAA. And... well I tried to
think of the desert again and I saw the wild west and the gun slingers. But no
mater how hard I tried I couldn't separate the desert from the people. So I
gave into my true nature... I'm a people person. I love good stories with good
characters. Give me a desert and I'll see pyramids and pharos, huge blocks of
stone. But gun slingers and pharos and wise men seemed to be expected members
of the desert world. I wanted to introduce you to a new person one you were not
expecting to meet today. I tried to make an honest picture of a modern day
cowboy (though there are not many of them in Ohio) - just a guy with a pick-up
and a dog. The trick was to be specific enough to make you feel like you know
this guy. What kind of truck? What kind of dog? What does he do? What's going
on? To get at this I had to leave clews for you. If you would like to discover
these details yourself, please skip reading "Evolution of the Image" below
since I give away some of the secrets.

EVOLUTION of the IMAGE
(I'm including several small test renderings in a zip file to illustrate this
section)
As the image developed the relationship of the camera, man and environment
gradually changed. At first he was at a payphone with his broken down truck
just a few feet away. I put a huge 3D sign in the back of the truck that said
"Dusty Cactus" and had a cactus symbol on it. The view was very wide so you
could see a respectable attempt at doing a desert landscape. The cactus and the
name Dusty Cactus stuck in my mind. It seemed extremely funny to me and I was
quite pleased with myself. But my sub-topic was this guy. And you could not get
a good look at him with so much desert around. So I moved the camera closer to
him. I put it close to the ground by the truck. This was a very exciting angle
because the lines of the truck formed long diagonals. But now you couldn't see
the sine as well. I kept moving the Camera around while I added and removed
objects. I got rid of the phone booth - it obscured the man too much. I added a
dog. Eventually I tried making the man look at the dog and suddenly there was a
great duo where before there were isolated beings looking off into space. By
this time the dog and the man dictated the camera angle. I had to get the right
view to show off these two and the best view I could find was looking at the
side of the truck. That was bad news. I lost the chance to have the sign in the
back of the truck AND I lost the drama of the diagonal lines (plus a really
cool bumper sticker). I went back to work on the surroundings. I used the side
of a house to get back my diagonals. The vanishing point is centered on the man
helping to focus our attention on him. I painted the sign on the side of the
truck and added "Desert Tours" to it. The snake had been in the picture for a
long time. At first he was mid way through changing the tire when interrupted
by the dreaded (venomous) diamond back rattlesnake. In the end the snake is
just an "Easter egg" (a hidden prize for those who find him). I wonder if the
dog is trying to tell the man about the snake. And the house... is that the
headquarters of Dusty Cactus Desert Tours?


DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 

All of the objects were modeled and textured by me for this competition.

Modeling
A million years ago I was a fine art painting student working on my BFA. I
worked a lot from human models. So I'm not timid about working with them in 3D.
But the truck was really a problem. I had exactly two photos of the 1965 GMC
short bed (step side) truck. And both were quarter angle views rather than
straight at the side and straight at the front. I tried to examine the
proportions of the truck using the rules of linear perspective but that was
very cumbersome and not very accurate. I instead tried a less technical
approach. I rendered my truck from the same view as the trucks in the pictures
and then lined up the rendering over the photo as a PhotoShop layer. I had to
render a dozen times to get the camera angle and FOV to match the real world
one but once that was done I could flip back and forth between the two and see
what needed to be longer, shorter or stay the same. Still I needed to guess a
little. There were parts of the truck that I just couldn't see. So I used other
photos of similar GMC trucks as reference.

The man was easy compared to the truck (even though I don't have Poser or
Character Studio). As I said I have a reasonable idea of what people look like.
But unlike the truck, the man needed to have a skeleton, which takes a good bit
of time. The idea of "bones" is pretty cool. You have to create a skeleton out
of simple shapes (and\or "bone" objects). It works pretty much like real bones.
When a bone bends or twists it deforms the outer skin. To bend the arm you need
only bend the arm bones. But first you need to attach the bones to the skin and
adjust the influence each bone has over the vertices that make up the arm.
There's quite a bit of details I'm leaving out but that is the general idea.

The dog... well, I didn't have time to do a full skeleton for him. So I modeled
him with his legs apart then broke the legs off, rotated them into the position
I wanted and stitched them back on.

The bird was very fast to do. It started it's life out as a sphere (like an
egg). I squeezed and stretched it into the overall shape of the bird - a lot
like you would do with a ball of clay. I didn't worry about feet or eyes or any
of that since he was meant to appear as a small silhouette.

I came to a revelation this time around regarding modeling. First, before you
start look at the thing for difficult parts. Like the truck's door handle has a
recessed area under it and the hole for the window has rounded corners. Once
you know the trouble spots, it might be best to model each separately then join
them together into a single mesh. This realization has helped me greatly.
Here's another example. The man is modeled with his legs at a 90_ angle. This
is necessary for adding bones later. But it's not so easy to make his boots
when they are not lined up horizontally and vertically with the grid. So... I
did the boots as separate objects. Then it was really easy to join them to the
legs. I didn't even have to worry about the seam since the boots go into the
legs of the pants. Probably half of you are saying "it took you four years to
discover that?!?!" I've never read this anyplace so I figured I better pass on
the tip for the other half who didn't know that like me.

Textures
Of all of the textures, the truck and the dog were the hardest to do. In both
cases I had to divide up the polygons into many separate mapping groups. Then
each group could be assigned a UVW Mapping modifier... Ok that sounded
cryptic... I give you just wrapping paper and a dog and a huge real of tape.
Even though the dog stays still for the process It's nearly impossible to wrap
him and not have wrinkles. The only way to do the job is to divide up the
complex shape into smaller bits (it's still all one mesh but subsets of that
mesh are mapped independently). For example the front legs each have a
cylindrical map type with the seam in the back edge of the leg where it is less
visible. The neck of the dog, his torso and his head are mapped separately. You
can't see the results of mapping until the texture is applied. Usually it's
best to use a procedural checkerboard pattern to test for seams, stretch marks,
and inconsistent scaling. With something like a dog or a rusty truck you have
to map it a couple of times before it's 100% correct. At that point you can
create a real texture map for it.

Mostly I like bitmaps over procedural maps because it allows me more control
over textures in relation to the geometry. The dried mud on the truck would be
hard to do procedurally because its location is intimately connected to the
location of the wheels. I did use a multi-layered procedural map for the
ground. The concrete walkway is a bitmap also. For that I made four tiles so it
would be less easy to recognize the repetition. I must admit a flaw that you
can't see. All of the bitmaps are too large. I'm not brave enough to make them
smaller. In games, it's amazing how small the maps are! Like all the maps for
an airplane fit in one 255 by 255 bitmap. My bitmaps are more like 1000 by 1000
pixels. That adds to the rendering time but if I ever need to render a larger
image the maps should still look good.

Lighting
There are only two lights. One is a "target direct" light for the sun. This
light type produces parallel light rays so shadows do not become larger than
the objects that cast them. The other is a "sky light". That one mimics the
soft light from the sky. In older versions of Max people would create a dome of
omni lights (a point light source with 360_ light cone). It is vastly easier to
use a sky light and it renders faster too.

Rendering
There are several options for renders within Max. There is a built in radiosity
render and an alternative one called "Light Tracer". Light Tracer is easier to
set up and generally works well for outside lighting. So I used it. One of the
neat little parameters for Light Tracer is number of bounces. Zero is the
default. Zero means that the light will not bounce off of objects and
illuminate other surfaces. One means the light can bounce one time (that's what
I used). The higher the number the more realistic the lighting is but at a
heavy cost to rendering time. Ten is the maximum setting (use that if your
planning on going on vacation while it renders). There are many other settings
but I think this may bore more people than it would help. If you would like
more information please don't hesitate to ask.

Links
I found an amazing wealth of information regarding deserts on-line. I'd like to
pass some of the most interesting and helpful links to you. Many of these have
amazing photos!

All About the World's deserts (Very informative and concise):
http://www.infoplease.com/ipa/A0778851.html

HooDoos (you can see them but you can't believe them):
http://images.google.com/images?hl=en&lr=&ie=UTF-8&q=hoodoo

Misc. Photos:
http://community.webshots.com/photo/51609681/51609943vYWpip

Has good desert pictures (in the Arches, Bryce Canyon, Grand Canyon,
Canyonlands, and West US Nature sections):
http://mypage.bluewin.ch/gallery/photo.htm

Google search for art about deserts:
http://images.google.com/images?q=(art+OR+painting+OR+drawing+OR+watercolor)+AND+
(desert+OR+cactus+OR+indian+OR+cowboy+OR+camel+OR+dune+OR+Sinbad+OR+%22middle+ea
st%22)&hl=en&lr=&ie=UTF-8&start=60&sa=N